Article

Simultaneous determination of captopril and hydrochlorothiazide in human plasma by reverse-phase HPLC from linear gradient elution.

Department of Pharmacy, Fudan University, Shanghai 200032, PR China.
Journal of Pharmaceutical and Biomedical Analysis (impact factor: 2.97). 06/2006; 41(2):644-8. DOI:10.1016/j.jpba.2005.12.007 pp.644-8
Source: PubMed

ABSTRACT A simple, rapid and sensitive high-performance liquid chromatographic method for the simultaneous determination of captopril and hydrochlorothiazide in human plasma samples was developed. Captopril was derivatized with 2,4'-dibromoacetophenone (pBPB) to form a captopril-pBPB adduct. From acidified serum plasma samples, the hydrochlorothiazide and derivatized captopril was extracted with 5 ml ether, then with 5 ml dichloromethane. Effective chromatographic separation was achieved using a C(18) column (DIAMONSIL 150 mmx4 mm i.d., 5 microm) based on an acetonitrile-trifluoroacetic acid-water gradient elution at a flow rate of 1.2 ml/min. The internal standard (IS), derivatized captopril and hydrochlorothiazide were detected at 263 nm and were eluted at 4.2, 6.8 and 16.9 min, respectively. No endogenous substances were found to interfere. The limit of quantification for hydrochlorothiazide and derivatized captopril in plasma were 3.3 and 7 ng/ml. The calibration curve for derivatized captopril showed linearity in the range 20-4000 ng/ml, with a regression coefficient corresponding to 0.9993 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The calibration curve for hydrochlorothiazide showed linearity in the range 10-1200 ng/ml, with a regression coefficient corresponding to 0.9999 and the coefficient of the variation of the points of the calibration curve being lower than 10%. The method was suitably validated and successfully applied to the determination of captopril and hydrochlorothiazide in human plasma samples.

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Keywords

5 microm
 
5 ml dichloromethane
 
5 ml ether
 
acetonitrile-trifluoroacetic acid-water gradient elution
 
acidified serum plasma samples
 
calibration curve
 
Captopril
 
captopril-pBPB adduct
 
derivatized captopril
 
DIAMONSIL 150 mmx4
 
Effective chromatographic separation
 
endogenous substances
 
flow rate
 
human plasma samples
 
internal standard
 
linearity
 
plasma
 
regression coefficient corresponding
 
sensitive high-performance liquid chromatographic method
 
simple
 

Taomin Huang